<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>

    <script type="text/javascript">
        // var a = 10;
        // var b = "10";
        // document.write(a === b);

        //     输出语句
        confirm("hello")    //弹出一个对话框
        console.log("hello world")   //在浏览器控制台输出内容

    </script>
</head>
<body>
    <div id="div1">
        我是div标签
    </div>

</body>
    <script type="text/javascript">
        var a = document.getElementById("div1")
        a.innerHTML = "我是h1标签";

    </script>
</html>